Cooling apparatus



24, 1942. in. D. massing; I 2,303,063

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" 'ywm 'ar-ronniyl Patented Nov. 24, 1942 "UNITEDISTVATES PATENT OFFICE- COOLING APPARATUS tion of Delaware Application August 2, 1940, SerialNo. 349,416

2 Claims.

This invention relates generally to apparatus 7 for effecting controlled cooling of various liquid materials. The invention is particularly applicable to cooling operations involved in-the processing of various food materials.

In the processing of various liquid food materials, such as tomato pulp, it is frequently desirable to rapidly chill the material to a predetermined temperature level. For example, in the processing of tomato pulp preparatory to introducing the material into cans, the pulp is subjected to'evaporation to concentrate the same, and it is delivered from the last evaporating stage at a temperature in excess of 212. F. Where ordinary canning methods are employed, it is desirable to cool the concentrate to a temperature below 212 F. before it is introduced into the cans. Rapid cooling is desirable in order to minimize the time period durin which the material is subjected to temperatures in ex-' 1 near the outlet I2b, there is a zigzag metal strip cess of 212 F. Also it is desirable to chill the liquid material to a definite temperature level 'which is still sufllcient to efiect sterilization, as

for example 190 F., irrespective of changes in the quality or'temperature of the material being discharged from the evaporator.

It is an object of the present invention to pro-, 'vide cooling apparatus particularly adapted for services such as outlined above. Our apparatus is capable of rapid chilling of materials such as tomato paste from temperatures in excess of 212 F., as for example from 214 to 230 F.,'to a deflnite temperature level of'say 190 F. The invention is characterized by a novel method for handling the chilling medium and for effecting automatic control of the chilling medium in accordance with temperature variations of the cooled material leaving the apparatus.

Additional objects and features of the invention will apepar from the following description in which the preferred embodiment of the in- .vention has been set Iorth in detail.

- Referring to the drawing:

Figure 1 is a diagrammatic side elevational view, partly in cross section, showing the present invention; and

Figure 2 is an enlarged cross sectional detail showing a part of the heat transfer tube I2.

Our apparatus makes use of a heat exchange unit formed to provide an attenuated path for flow of the liquid material to be cooled, and another separate flow path for a cooling liquid like I3, for a purpose to be presently explained. The inlet Ila connects to the discharge side of a liquid circulating pump I6, and the inlet side of this pump connects with the outlet II'b through the throttling valve II. Pump I6 therefore continuously recirculates cooling water through the pipes II. The inlet side 01' pumpIS is also connected to a source of additional cooling liquid at substantially constant pressure. Thus a stand ,pipe I8 is shown, with'its inlet I80. connected to a source of cool water, and with its outlet I ah connected to the inlet side of pump I6. The overflow pipe I9 extendin through p-ipe I8 determines the height of the liquid column maintained in pipe I8, and therefore serves to maintain a constant head or pressure at the outlet I 8b.

To effect a controlled bleeding off of recirculated cooling liquid, a diaphragm control valve water. The heat exchange unit I0 shown in the drawing consists of pipes I I connected at their upper ends, and within which there is a tube or i 2| has its inflow side connected to the outlet I lb. The pressure chamber'of this valve is shown connected to a controller 22, which in turn is connected by the control line 23 to the temperature responsive bulb 24. Bulb 24 is located in the outlet end of tube I2, so that it is intimately contacted with material being withdrawn at I217. The controller 22 may be any one of a number of suitable devices for this purpose. For example, it may be adapted to apply varying pneumatic pressures to the operating chamber of valve 2|, responsive to variations in the temperature of the bulb 24.. Thus with an increase in temperature of bulb 24, valve 2| is operated to open the same and thus increase thebleed-ofl of cooling water. Conversely, when the temperature of the bulb 24v decreases, valve 2| is moved towards closed position to decrease the drawofi of water.

For reasons to be presently explained, it is desirable to place a small back pressure head upon the discharge side of valve 2I. For this purpose I- have shown a stand pipe 26 having its lower end connected to valve 2 I. Overflow pipe 21 extending within pipe." determin'es'the height of Operation of the is connected toreceivehot [sureis V flow rate through outlet other words,

' culation through stancesthe rate-oi 'changesin thebackpressurehead to change the flow making changes in the liquid column which is maintained as a back e head.

apparatus described above is as follows: It will be tomato paste at temperatures above 212 It, and that this paste is being cooled to a definite temperature of say 190? 1". as it leaves the outlet lib. Pump ll operatu to continuously recirculate cooling water through thepipes ll. Valveil iscontrplledinaccordance with the temperature or the cooled tomato paste leaving outlet lib. Normally a certain amoimt oi bleed-oi! occurs continuously, and a slight increase in temperature of the tomato paste increases the bleed-oil, and conversely a reduction the bleed-om .Throtupon the discharge side of pump I, which presample to discharge liquid through valve il. against the back pressure caused by pipe il. Depending directly upon the bleed-oi! of water through valve il, additional amounts of cooling water are supplied to theinlet'of pump I. from the stand pipe II. v

The flow rate of water into the stand pipe ll, irom'inlet lid, is at-all lib to the Pump II. In there is always an excess of water discharging through the overflow pipe ll. Thus a constant head or pressure is maintained at the outlet 'llb, whi h makes for smoother and more accurate control. The rate of continuous recirpump I. is normally many times the rate of introduction of additional water from the stand. pipe ii. For example, in typical inrecirculation through pump It may be from 50 to 100 times the rate of introduction oi?- cool water from the stand pipe. Such recirculation of cooling liquid makes for rapid cooling, and at the same time it prevents the apparatus from 'being too critical or erratic in operation. r

Use of a definite back pressure upon the valve ii facilitates adjustment oi the apparatus to a variety 01' conditions. For example, by making it is possible rates through valve 21 without the size oi'the valve orifice.

The temperature of the water being recirculated by pump It will range somewhat less than the temperature of the cooled material being withdrawn from outlet lib. For example, where this outlet temperature is 190 It, the temperature of the liquid on the discharge vary from 120 times greater than the presumedthattheinlet lidfore contacting valve l'l causes a building up of pressure responsive to the temperature of the side oi pump it may to 15o I". For the same example, 55

' to deliver themake-upwatermpplledtostandpipe llwill be somewhat lower in temperature. as for example atemperatureoiirombbto'lo' I".

Them strip irregular controller actionin that in, flowing aboutthe edgesoithis stripthestreamofmaterialbelng cooledisthoroulh yintermixedbethe bulb il.

0! tube Ii servestoimii for the entire leng h prove the heat transfer.

We claim: I

1. In apparatus for controlled cooling of liquid food materials, a heat exchange unit having-one iiow path for cooling liquid and another iiow path for the liquid food material to'be cooled, a recirculating pump having its discharge connected cooling liquid to the heat exchange unit and having its inlet connected to receive cooling liquid discharged from said tmit, means ior supplying additional cooling liquid to the inlet side of the pump, temperaturecontrolled valve means for venting oil a portion of the cooling liquid discharged from said unit, means providing a constant pressure head opposing the bleeding ofl'ot a cooling liquid, and posed between said-unit and the inlet side of the said last means serving to maintain pressure on the discharge side of the pump to enable venting of liquid through the temperature controlled valve means.

2. In apparatus for contro cooling of liquid food materials, a heat exchange unit having one flow path for cooling liquid and another flow path for eiie'cting controlled bleeding on oi a portion of the cooling liquid discharged from said unit OOOIQd material leaving the heat exchange unit, means providing a constant pressure head opposing the bleeding oil. oi cooling liquid, and .a throttling valve interposedbetwe'en the point of bleed-oi! oi cooling liquid from said unit and the inlet side of the pump, said throttling valve forming a iiow restricting orliice serving to maintain pressure on the discharge side oi the pump to cause how 0! cooling liquid through said bleed-oil means.

' DAVID D. JOHN M. MEYER.

I8 (Fig. 2) tends to prevent flow restrictin means interexchange unit and 

